1. Field of the Invention
This invention relates to a disc reproducing apparatus for reproducing a disc-shaped recording medium.
2. Description of the Related Art
In a reproducing apparatus for a compact disc (CD), which is a disc-shaped recording medium having the audio information recorded thereon, various sorts of indication based on the disc reproducing information are used for enhancing convenience in use.
It has been known to reproduce and display the program number, that is called track number, recorded on a Q-channel subcode as later explained as a mode 1, or the elapsed time allocated to each track number, as the display information based on the disc reproducing information in a conventional CD reproducing apparatus.
FIG. 1 shows an example of an optical disc, such as CD.
Referring to FIG. 1, an optical disc 101 has a center aperture 102 and, looking from the inner rim towards the outer rim of the disc 101, includes a lead-in area 103, as a table-of-contents (TOC) area or a program management area, a program area 104 having program data recorded therein, and a program end area or a so-called lead-out area 105. In an audio reproducing optical disc having the audio information recorded therein, audio data is recorded in the program area 104, while the total recording time, the total number of recorded programs and the program-based recording time and so forth, are managed by the lead-in area 103. When the readout of the audio data in the program area 104 by the disc reproducing apparatus has come to a close, and an optical pickup has reached the lead-out area 105, the disc reproducing apparatus completes the reproducing operation for the optical disc designed for audio reproduction.
FIG. 2 shows an example of the above-described disc reproducing apparatus.
The disc reproducing apparatus reads out the audio data of the optical disc 101 designed for audio reproduction with an optical pickup 102 and processes the audio data with a digital signal processing circuit 116 to generate playback data which is outputted at a digital signal output terminal 125 or at left and right channels of an analog signal output terminal, not shown.
The optical pickup 112 of the disc reproducing apparatus reads out the audio data of the optical disc 101, that is the so-called RF signals, and sends the signals to an analog waveform shaping circuit 114, while sending a focusing servo signal to a focusing servo circuit 120 and sending tracking servo signals and thread servo error signals to a tracking servo circuit 121.
The analog waveform shaping circuit 114 shapes the waveform of the RF signals from the pickup 112 and sends the shaped signals to a synchronization detection circuit 115 and a clock generating circuit 117. The clock generating circuit 117 generates reproducing clocks for the RF signals based on the RF signals from the analog waveform shaping circuit 114. The generated reproducing clocks are sent to the synchronization detection circuit 115, digital signal processing circuit 116 and to a rotation servo circuit 122. The synchronization detection circuit 115 detects a frame synchronization pattern from the RF signals and sends the signal, from which frame synchronization pattern has been detected, to the digital signal processing circuit 116. The digital signal processing circuit 116 decodes the RF signals, from which the frame synchronization pattern from the digital signal processing circuit 116 has been detected, based on the reproducing clocks from the clock generating circuit 117 and reference clocks sent from the quartz oscillator 119, and sends the decoded signals to a subcoding detection circuit 118, a D/A conversion circuit 123 and to a digital signal output terminal 125. The D/A conversion circuit 123 converts the digital signals into analog signals which are sent to an audio amplifier 124. The audio amplifier 124 amplifies the analog audio signal from the D/A conversion circuit 123 and send the amplified signal to the right and left channels of the analog signal output.
The subcoding detection circuit 118 detects data of subcode P and Q channels, as later explained, and sends the data of the respective channels to the tracking and thread servo circuit 121.
The subcoding detection circuit 118 detects data of the subcode P and Q channels from the digital signal of the digital signal processing circuit 116 and sends the data of the respective channels to a tracking and thread servo circuit 121.
The focusing servo circuit 120 generates a focusing operation driving signal, based on the focusing error signal from the optical pickup 112, and sends the focusing operation driving signal to the pickup 112 for controlling the focusing operation of the optical pickup 112. The rotation servo circuit 122 generates a rotation driving control signal, based on playback clocks from the clock generating circuit 117 and the reference clocks from the quartz oscillator 119, and sends the rotation driving control signal to the spindle motor 113 for controlling the rotational operation of the spindle motor 112.
The tracking and thread servo circuit 121 generates tracking control driving signals based on the tracking servo error signals and the thread servo error signals from the pickup 112 and sends the generated tracking control driving signals to the pickup 112 for controlling the tracking operation of the pickup 112. The tracking and thread servo circuit 121 generates track position control signals based on data from the P and Q channels supplied from the subcoding detection circuit 118 and sends the position control signals to the pickup 112 for controlling the track positions of the pickup 112 for the programming mode.
The data of the subcode and the P and Q channels as described above are now explained.
The signals recorded on the optical disc designed for audio reproduction are sampled with the sampling frequency of 44.1 kHz, with each sample or word being of 16 bits. The 16-bit-per-word sampled data is split into a symbol of upper 8 bits and another symbol of lower 8 bits and error correction coded or scrambled on the symbol basis so that every 24 symbols of the data make up a frame. This corresponds to 12 original samples, that is 6 samples each of the stereo left and stereo right channels.
The signals assembled into one such frame are of such a format in which each frame 135 has a synchronization pattern data area 131 of 24 channel bits, a subcoding area 132 of 14 channel bits, a program data area 133, a parity data area 134, another program data area 133 and another parity data area 134. The program data area 133 is made up of 12 symbols D1 to D12 each being of 14 channel bits, while the parity data area 134 is made up of parity data P1 to P4 each being of 14 channel bits. The areas or data portions are interconnected by junction areas each being of 3 channel bits. Thus, each frame 135 is made up of a sum total of 588 channel bits of data.
FIG. 4 shows 98 of the above frames 135 collected together and re-arrayed so that the above areas and data portions of each frame will be contiguous to one another in the vertical direction. The set of data shown in FIG. 4 in its entirety is also termed a frame. However, for distinction from the frame made up of 588 channel bits, the set of data of FIG. 4 in its entirety, made up of 98 frames, is termed a subcoding frame. This subcoding frame is made up of a frame synchronization pattern portion 136, a subcoding portion 137 and a data/parity portion 138. The subcoding frame is equivalent to {fraction (1/75)} second of the usual CD reproducing time.
The subcoding data, inclusive of the P-channel data and the Q-channel data sent from the subcoding detection circuit 118 of FIG. 12, is recorded on the subcoding portion 137 of FIG. 4. The subcoding portion 137 is of a structure such that 98 frames of from frame F0 to frame F98 make up one block, that is the above subcoding frame, as shown in FIG. 15. The frames F01 and F02 are block synchronization patterns, while representing out-of-rule patterns S0 and S1 of the eight-to-fourteen modulation (EFM) system. The subcoding detection circuit 118 detects the above synchronization patterns to form a one block of the subcoding portion 137. The respective bits of the that frames form frame F01 to frame F98 make up channels of from channel P to channel W. For example, the P-channel is constituted by portions of the patterns S0 and S i and P01 to P98.
The data of the six channels of from channel R to channel W are used for special uses, such as still pictures or representation of karaoke letters. The data of the P-channel and the Q-channel are used for controlling the pickup track position control, that is for controlling the accessing operation for the pickup.
The P-channel is used exclusively for recording a signal xc3xa60xe2x80x2 in the lead-in area 103, a signal xc3xa61xe2x80x2 and a signal xc3xa60xe2x80x2 between the music and music and otherwise in the program area 104, respectively, and a signal repeated between xc3xa60xe2x80x2 and xc3xa61xe2x80x2 at a pre-set period in the lead-out area 105. The P-channel information is used as the information for locating the program leading end portion.
The Q-channel information is used as the address information used by the pickup 112 of FIG. 2 to perform the above accessing operation. Each block of the Q-channel, that is each subcoding frame, has a structure made up of a synchronization bit block 141, a control bit block 142, an address bit block 143, a data bit block 144 and a cyclic redundancy code (CRC) bit block 145, as shown in FIG. 6.
The synchronization bit block 141 is made up of 2-bit data for recording a portion of the synchronization pattern. The control bit block 142 includes 4-bit data for recording the number of audio channels, emphasis or data used for identifying digital data. The 4-bit control bit data in the control bit block 142, that is the control bit data, is now explained. FIG. 7 shows the 4-bit control bit data. In the control bit data 142a, xe2x80x9c0000xe2x80x9d denotes 2-channel audio without preemphasis. In the control bit data 142b, xe2x80x9c1000xe2x80x9d denotes 4-channel audio without pre-emphasis. In the control bit data 142c, xe2x80x9c0001xe2x80x9d denotes 2-channel audio with pre-emphasis. In the control bit data 142d, xe2x80x9c1001xe2x80x9d denotes 4-channel audio data with pre-emphasis. In the control bit data 142e, xe2x80x9c0100xe2x80x9d denotes a data track other than an audio track in a data read-only optical disc, such as a CD-ROM.
In FIG. 6, the address bit block 143 has 4-bit data for recording a control signal specifying the format or a sort of data in the data bit block 144.
In FIG. 6, the data bit block 144 has 72-bit data. If, for example, the address bit is xe2x80x9c0001xe2x80x9d, the data bit block 144 is made up of a program number portion 151, an index portion 152, an elapsed time minute component portion 153, an elapsed time second component portion 154, an elapsed time frame number portion 155, a 0-portion 156, an absolute time minute component portion 157, an absolute time second component portion 158 and an absolute time frame number portion 159, as shown in FIG. 8. Each portion is comprised of 8-bit data. Meanwhile, a frame of the frame number recorded in the elapsed time frame number portion 155 and in the absolute time frame number portion 159 denotes the subcoding frame.
The program number portion is represented by two digits in the binary coded decimal notation. For example, xe2x80x9c00xe2x80x9d denotes a at a beginning portion of data readout, that is a so-called lead-in track, while xe2x80x9c01xe2x80x9d to xe2x80x9c99xe2x80x9d denote the program numbers. The number in the hexadecimal notation xe2x80x9cAAxe2x80x9d denote data read-out end, that is a so-called lead-out track. In the following description, a suffix xe2x80x9chxe2x80x9d is appended to a number represented in hexadecimal notation such as, for example, xe2x80x9cAAhxe2x80x9d.
The index portion 152 is represented by two-digit BCD. For example, xe2x80x9c00xe2x80x9d denotes transient stop, that is pause, while xe2x80x9c00xe2x80x9d to xe2x80x9c99xe2x80x9d denote finer divisions of the program unit.
The elapsed time hour component portion 153, the elapsed time second component portion 154 and the elapsed a time frame number portion 155 denote the elapsed time in the track each by two digits, that is a sum total of 6 digits. Since one second is 75 frames, the elapsed time frame portion 155 is represented by xe2x80x9c00xe2x80x9d to xe2x80x9c74xe2x80x9d. The elapsed time frame number is decremented between tracks so that the number will start from zero at the initial position of each track. The 0-portion 156 is stuffed with xe2x80x9c0xe2x80x9ds.
The absolute time hour component portion 157, absolute time second component portion 158 and the absolute time frame number portion 159 are each represented by 2-digit BCD, totaling at 6-digit BCD. In the lead-in area 103 of FIG. 1, if the index portion 152 is xe2x80x9cA0hxe2x80x9d, the absolute time component portion 157 is represented by the first program number, whereas, if the index portion 152 is xe2x80x9cA1hxe2x80x9d xe2x80x9cA1hxe2x80x9d, the absolute hour component portion 157 is represented by the last program number. Both in case the index portion 152 is xe2x80x9cA0hxe2x80x9d and in case the index portion 152 is xe2x80x9cA1hxe2x80x9d, the absolute time second component portion 158 and the absolute time frame number portion 159 are both xe2x80x9c0xe2x80x9d. If the index part 152 is xe2x80x9cA2hxe2x80x9d, the absolute time with which the lead-out area 105 of FIG. 1 starts is recorded in the absolute time minute component portion 157, absolute time second component portion 158 and in the absolute time frame number portion 159.
In the program area 104 of FIG. 1, the time which advances in an additive sense each time 0 comes from the start position of pause of the first program that is the absolute time, is recorded in the absolute time minute component portion 157, absolute time second component portion 158 and in the absolute time frame number portion 159.
The CRC bit block 145 of FIG. 16 is a portion having 16-bit data. In the CRC bit block 145 is recorded data for error detection of the CRC.
The programming mode is realized by detecting the information employing data of the Q-channel data as described above by the subcoding detection circuit 118 of the disc reproducing apparatus as shown in FIG. 2, decoding the information and by controlling the accessing operation of the pickup 121 by the tracking and thread servo circuit 121 based on the decoded signal.
Since the number of programs and the time information concerning the individual programs are recorded in the subcode Q-channel, this information may be displayed on a display device, such as LCD, the serial number of the currently played program in the sequence of the program numbers of the audio reproducing optical disc, the elapsed play time or the absolute time from the beginning can be checked visually.
Meanwhile, the text information, recorded in the subcode, is necessarily digitally outputted during readout of the TOC information. If rights are accrued in the text information, the information may be illicitly duplicated, since there lacks means for controlling the digital outputting of the text information, thus raising troubles in connection with such rights.
It is therefore an object of the present invention to provide a disc reproducing apparatus in which at least a digital output of the text information can be interrupted for a pre-set time.
The present invention provides a disc reproducing apparatus in which main data, management data for managing the main data and subsidiary data ancillary to the main data are digitally outputted from a disc-shaped recording medium having the main data, management data and the subsidiary data recorded thereon. The disc reproducing apparatus includes readout means for reading out the main data, management data and the subsidiary data from the disc-shaped recording medium, detection means for detecting a flag specifying inhibition of permission of digitally outputting the subsidiary data from the subsidiary data read out by the read-out means, and control means for inhibiting or permitting the outputting of the subsidiary data from the digital output terminal based on the flag detected by the detection means.
The present invention also provides a disc-shaped recording medium including main data, management data for managing the main data and subsidiary data ancillary to the main data, wherein an identifier inhibiting or permitting duplication of the subsidiary data is included in the subsidiary data.
With the disc reproducing apparatus according to the present invention, if, when reproducing the disc-shaped recording medium having main data and the subsidiary data recorded thereon, the specified information, such as text data, is recorded as the subsidiary data, and a specified flag pertinent to the specified information, such as a copying inhibiting flag, is set in making the recording, it becomes possible to selectively invalidate only the subsidiary data in transmitting the main data and the subsidiary data, such that, if rights have been accrued to the specified information, it becomes possible to inhibit illicit copying of the specified information.